Some displays have a spatial light modulator, such as a LCD panel, illuminated by a backlight. Light from the backlight interacts with the spatial light modulator which spatially modulates the light so as to present images to a viewer. The images may be still images or video images for example. In some such displays, the backlight has different areas that are separately controllable so that the intensity of light emitted by the backlight can be made to vary in a desired way over the spatial light modulator. This can provide improved images. Examples of displays that have spatially variable backlights are described in the following patent publications:
PCT Patent Application Publication Nos. WO02/069030, WO03/077013, WO2006/010244 and WO2008/092276.
There is consumer demand for displays that are thin front-to-back. Such displays can be more easily accommodated in some locations than thicker displays and are also less bulky in appearance than thicker displays.